Can Viruses Spread Through WiFi? Here’s What You Need to Know

Published: February 20, 2025

WiFi keeps us constantly connected, whether we’re working, streaming, or chatting with friends. But while we enjoy the convenience of wireless networks, they also create opportunities for cybercriminals to exploit security gaps.

We often get asked: Can viruses spread through WiFi? So in this article we’ll dive deep into this topic and also look at how WiFi networks might carry ransomware and whether your router can be infected.

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Can Viruses Spread Through WiFi?
Can Ransomware Spread Over WiFi?
Can Routers Get Viruses?
Signs That You’re Connected to a Compromised WiFi Network
How to Protect Yourself from WiFi-Based Malware Attacks
Final Thoughts

Can Viruses Spread Through WiFi?

In short, yes, viruses and malware can spread through WiFi. When a device connects to a compromised network, it can become vulnerable to attacks. Cybercriminals can exploit security gaps in networks and devices to distribute malicious software.

WiFi is inherently more exposed than wired connections because it broadcasts over radio waves. This wireless nature can allow malicious actors to intercept data or inject malware into network traffic without needing physical access.

Here’s how malware can spread through WiFi networks:

Network Infiltration: Hackers may breach an unsecured or poorly protected network by exploiting outdated router firmware or weak security protocols such as WEP (Wired Equivalent Privacy), which is known to be highly vulnerable to attacks.
Device-to-Device Infection: Once in a network, malware can spread between connected devices. For example, a virus may spread through file-sharing services, shared network folders, or poorly configured network services.
Propagation Techniques: Cybercriminals often use phishing emails, spoofed websites, and pop-ups to trick users into downloading malware. Once on a device, the malware may then spread to others on the same WiFi network.

One notable example of a WiFi-based threat is a Man-in-the-Middle (MITM) attack. In this type of cyberattack, a hacker positions themselves between a user’s device and the Internet, intercepting and potentially altering the data being transmitted.

This is especially dangerous on public or poorly secured networks, where attackers can steal login credentials, inject malicious content into web pages, or redirect users to fake websites designed to harvest sensitive information.

Can Ransomware Spread Over WiFi?

Ransomware is a highly disruptive form of malware that encrypts your data and demands payment for its release. While ransomware isn’t typically designed to autonomously spread over WiFi, it can still infiltrate a network through various tactics.

Below are three scenarios where ransomware might spread via WiFi.

Initial Entry via Network Exploitation

If a hacker breaches a network by exploiting a vulnerable router or connected device, they can deploy ransomware payloads to other devices on the network.

Lateral Movement

Once ransomware infects one device, it may exploit trust relationships between devices. For instance, if file-sharing permissions are not restricted, ransomware can replicate itself by encrypting files stored on network drives or shared folders.

Human Error and Social Engineering

Even if the ransomware itself lacks automated network-spreading capabilities, attackers may use phishing to target multiple users within the same WiFi network. Once infected, one compromised device can enable the attacker to spread the ransomware manually to other devices by accessing their shared resources.

Preventing ransomware attacks involves a combination of measures, including robust backups, endpoint protection software, and strict access control policies.

Can Routers Get Viruses?

Routers play a critical role in connecting all devices on a network to the internet. Unfortunately, they are increasingly targeted by cybercriminals due to their central role. A compromised router can give an attacker control over the entire network, allowing them to monitor traffic, steal data, and spread malware.

Here’s how routers can become infected:

Weak Credentials: Many older routers still use factory-default login credentials. Hackers can easily obtain these details from publicly available databases.
Firmware Vulnerabilities: Outdated firmware can contain unpatched security flaws. Attackers can exploit these flaws to take control of the router. One example of this is the rom-0 vulnerability.
Fake WiFi Hotspots: In some cases, cybercriminals create rogue WiFi networks that mimic legitimate ones. Unsuspecting users may connect to these networks, exposing their devices to malware.

Pro Tip: To secure your router, change the default password, update firmware regularly, and enable encryption protocols like WPA3 or WPA2.

Signs That You’re Connected to a Compromised WiFi Network

If a WiFi network has been compromised, your device could be at risk even if everything seems normal. Cybercriminals can manipulate network traffic, steal sensitive data, and even install malware on connected devices. Here are some telltale signs that you might be on an unsafe network:

Websites Look Strange: Pages may appear broken, display unusual fonts or colors, or contain unexpected pop-ups. This could indicate that attackers are intercepting and modifying your web traffic.
Security Warnings in Your Browser: If your browser alerts you that the connection is “not secure” or that a site’s certificate is invalid, it may suggest a hacker is trying to eavesdrop on your activity.
Slow Internet Speed: While normal network congestion can cause slow speeds, a compromised network may experience sluggish performance due to malware consuming bandwidth or hackers using your connection for illicit activities.
Unexpected Apps on Your Device: If strange apps suddenly appear on your phone or computer, it’s possible that malware was pushed to your device through the infected network.
Unusual Account Activity: Receiving security alerts about logins from unfamiliar locations could mean that cybercriminals intercepted your credentials while you were connected to a compromised WiFi network.
Your Router Settings Have Changed: If you find that your router’s DNS settings have been modified without your knowledge, it could indicate that a hacker has taken control and is redirecting your traffic to malicious sites.
Frequent Disconnections: If you’re constantly getting disconnected and reconnected to WiFi, attackers may be attempting to intercept your connection or perform a “man-in-the-middle” attack.

These signs may not always point to malware, but it’s crucial to investigate any unusual activity promptly.

How to Protect Yourself from WiFi-Based Malware Attacks

Preventing malware infections on WiFi networks requires a combination of best practices and security tools:

Secure Your Router: Use strong passwords, enable WPA2/WPA3 encryption, and regularly update your router’s firmware. Disable features like remote management unless absolutely necessary.
Avoid Public WiFi: Public networks are often unsecured and can be easily compromised. Use a VPN to encrypt your internet traffic when connecting to public hotspots.
Disable Auto-Connect: Prevent your device from automatically connecting to open networks without your consent.
Use Firewalls and Antivirus Software: Firewalls can block unauthorized network access, while antivirus programs can detect and remove malware before it spreads.
Be Cautious with Links and Downloads: Avoid clicking on suspicious links or downloading attachments from unknown sources, as these are common vectors for malware distribution.

Implementing these measures can significantly reduce the risk of falling victim to cyberattacks on WiFi networks.

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Final Thoughts

WiFi networks offer great convenience, but they also introduce cybersecurity risks. Understanding how malware can exploit WiFi is essential to safeguarding your devices and personal information.

By following best practices—such as securing your router, using strong encryption, and avoiding risky network behaviors—you can minimize your exposure to cyber threats.

If you suspect your device has been compromised, consider using a reputable anti-malware solution like Certo to scan for hidden threats.